Invasive Species in Forests and Rangelands of the United States
The introduction, establishment, and spread of invasive species in terrestrial and aquatic enviro... more The introduction, establishment, and spread of invasive species in terrestrial and aquatic environments is widely recognized as one of the most serious threats to the health, sustainability, and productivity of native ecosystems (Holmes et al. 2009; Mack et al. 2000; Pyšek et al. 2012; USDA Forest Service 2013). In the United States, invasive species are the second leading cause of native species endangerment and extinction, and their costs to society have been estimated at $120 billion annually (Crowl et al. 2008; Pimentel et al. 2000, 2005). These costs include lost production and revenue from agricultural and forest products, compromised use of waterways and terrestrial habitats, harm to human and animal health, reduced property values and recreational opportunities, and diverse costs associated with managing (e.g., monitoring, preventing, controlling, and regulating) invasive species (Aukema et al. 2011; Pimentel et al. 2005). The national significance of these economic, ecologi...
ABSTRACT Eighteen lodgepole pine (Pinus contorta Dougl. ex Loud.) stands, 19-32 years in age, wer... more ABSTRACT Eighteen lodgepole pine (Pinus contorta Dougl. ex Loud.) stands, 19-32 years in age, were surveyed for Scytalidium uredinicola Kuhlman et al. in west-central Alberta. The purpose of the study was to determine how hyperparasite incidence was affected by gall age, gall size, and the occurrence of western gall rust caused by Endocronartium harknessii (J.P. Moore) Y. Hiratsuka (Peridermium harknessii J. P. Moore). Such information was deemed valuable for evaluating the likelihood that S. uredinicola was functioning as a density-dependent constraint in the pathosystem and assessing the potential for using this fungus as a biological control agent. The hyperparasite was present in all stands, albeit at generally lower levels than previously reported, but there was little evidence that its incidence increased with increasing incidence of gall rust. The odds of hyperparasitism increased by a factor of 1.3 for each year of gall growth, following adjustment for gall size effects, and by a factor of 2.1 for each 1 cm increase in gall size, following adjustment for gall age effects. Since gall age and gall size were positively correlated, there was a strong positive relationship between the unadjusted effects of both age and size and the incidence of S. uredinicola. However, although the incidence of S. uredinicola consistently increased as galls became older and larger, low levels of the hyperparasite on small and young galls may limit the effectiveness of S. uredinicola as a biological control agent.
... Although silvicultural practices may reduce the impact of western gall rust (3,18), there are... more ... Although silvicultural practices may reduce the impact of western gall rust (3,18), there are few practical, direct meth-ods for control. Chemical ... Thus it likely is far less effective in reduc-ing the spread of western gall rust. Estimation ...
Quantify historical rates of black, scarlet and northern red oak mortality in the Ozark Highlands... more Quantify historical rates of black, scarlet and northern red oak mortality in the Ozark Highlands (Ecological section 222A) as a baseline against which to evaluate current levels of oak mortality. Use classification and regression tree (CART) analysis and/or related classification techniques to determine the tree and plot factors that are the best indicators of oak mortality. Determine the relative importance of factors that are determined to be statistically significant indicators of oak mortality. Apply the CART model using the latest available data from the Arkansas and Missouri FIA state-wide inventories (Cycle 5) to identify risk levels (severity). Use the CART model to identify FIA plots measured in the most recent Arkansas and Missouri statewide inventories that appear to show high risk (severity) of future oak mortality & map predicted extent.
Hayslett, M., Juzwik, J., and Moltzan, B. 2008. Three Colopterus beetle species carry the oak wil... more Hayslett, M., Juzwik, J., and Moltzan, B. 2008. Three Colopterus beetle species carry the oak wilt fungus to fresh wounds on red oak in Missouri. Plant Dis. 92:270-275.
Invasive Species in Forests and Rangelands of the United States
The introduction, establishment, and spread of invasive species in terrestrial and aquatic enviro... more The introduction, establishment, and spread of invasive species in terrestrial and aquatic environments is widely recognized as one of the most serious threats to the health, sustainability, and productivity of native ecosystems (Holmes et al. 2009; Mack et al. 2000; Pyšek et al. 2012; USDA Forest Service 2013). In the United States, invasive species are the second leading cause of native species endangerment and extinction, and their costs to society have been estimated at $120 billion annually (Crowl et al. 2008; Pimentel et al. 2000, 2005). These costs include lost production and revenue from agricultural and forest products, compromised use of waterways and terrestrial habitats, harm to human and animal health, reduced property values and recreational opportunities, and diverse costs associated with managing (e.g., monitoring, preventing, controlling, and regulating) invasive species (Aukema et al. 2011; Pimentel et al. 2005). The national significance of these economic, ecologi...
ABSTRACT Eighteen lodgepole pine (Pinus contorta Dougl. ex Loud.) stands, 19-32 years in age, wer... more ABSTRACT Eighteen lodgepole pine (Pinus contorta Dougl. ex Loud.) stands, 19-32 years in age, were surveyed for Scytalidium uredinicola Kuhlman et al. in west-central Alberta. The purpose of the study was to determine how hyperparasite incidence was affected by gall age, gall size, and the occurrence of western gall rust caused by Endocronartium harknessii (J.P. Moore) Y. Hiratsuka (Peridermium harknessii J. P. Moore). Such information was deemed valuable for evaluating the likelihood that S. uredinicola was functioning as a density-dependent constraint in the pathosystem and assessing the potential for using this fungus as a biological control agent. The hyperparasite was present in all stands, albeit at generally lower levels than previously reported, but there was little evidence that its incidence increased with increasing incidence of gall rust. The odds of hyperparasitism increased by a factor of 1.3 for each year of gall growth, following adjustment for gall size effects, and by a factor of 2.1 for each 1 cm increase in gall size, following adjustment for gall age effects. Since gall age and gall size were positively correlated, there was a strong positive relationship between the unadjusted effects of both age and size and the incidence of S. uredinicola. However, although the incidence of S. uredinicola consistently increased as galls became older and larger, low levels of the hyperparasite on small and young galls may limit the effectiveness of S. uredinicola as a biological control agent.
... Although silvicultural practices may reduce the impact of western gall rust (3,18), there are... more ... Although silvicultural practices may reduce the impact of western gall rust (3,18), there are few practical, direct meth-ods for control. Chemical ... Thus it likely is far less effective in reduc-ing the spread of western gall rust. Estimation ...
Quantify historical rates of black, scarlet and northern red oak mortality in the Ozark Highlands... more Quantify historical rates of black, scarlet and northern red oak mortality in the Ozark Highlands (Ecological section 222A) as a baseline against which to evaluate current levels of oak mortality. Use classification and regression tree (CART) analysis and/or related classification techniques to determine the tree and plot factors that are the best indicators of oak mortality. Determine the relative importance of factors that are determined to be statistically significant indicators of oak mortality. Apply the CART model using the latest available data from the Arkansas and Missouri FIA state-wide inventories (Cycle 5) to identify risk levels (severity). Use the CART model to identify FIA plots measured in the most recent Arkansas and Missouri statewide inventories that appear to show high risk (severity) of future oak mortality & map predicted extent.
Hayslett, M., Juzwik, J., and Moltzan, B. 2008. Three Colopterus beetle species carry the oak wil... more Hayslett, M., Juzwik, J., and Moltzan, B. 2008. Three Colopterus beetle species carry the oak wilt fungus to fresh wounds on red oak in Missouri. Plant Dis. 92:270-275.
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